linux-ext4 - Re: data corruption with ext4 (from 2.6.27.4) exposed by rtorrent

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 3 Nov 2008 16:51:44 +0100
From:	Jindrich Makovicka <makovick@...il.com>
To:	linux-ext4@...r.kernel.org
Subject:  Re: data corruption with ext4 (from 2.6.27.4) exposed by rtorrent

On Mon, 3 Nov 2008 16:34:10 +0100
Cryptooctoploid <cryptooctoploid@...il.com> wrote:

> On Mon, Nov 3, 2008 at 2:40 PM, Theodore Tso <tytso@....edu> wrote:
> > On Mon, Nov 03, 2008 at 12:42:11PM +0000, Roc Valles wrote:
> >> Some person already reported this. I'm having the same problem.
> >> http://marc.info/?l=linux-ext4&m=122557056518246&w=2
> >>
> >> rtorrent is a bittorrent client that makes heavy use of mmap
> >> instead of read/write to avoid needless duplication of data. It
> >> has exposed other bugs in the past (mmap bug in 2.6.19).
> >> http://libtorrent.rakshasa.no
> >> Downloading a big torrent (>2GB) with rtorrent triggers it more
> >> times than not. The bigger the torrent, the higher the likeliness
> >> of failure. When the torrent is finished, if a hash check is
> >> forced by pressing control-r on the torrent, some blocks will fail.
> 
> I have set up a debug torrent at:
> http://www.demonoid.com/files/details/1676328/?rel=1225725960
> 
> It contains four identical files that were generated with:
> dd if=/dev/zero of=zero.test0 count=1M
> 
> My upload speed is limited (512 kbit/s), but I hope this may help.

The following testcase was used to trigger the infamous MAP_SHARED
dirty flag bug. Maybe it could be of some help here too:

http://lkml.org/lkml/2006/12/27/180

-- 
Jindrich Makovicka


--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html